Answer:
weak bases
Explanation:
Leaving groups accept electron pairs. A strong base donates an electron pair while a weak base accepts an electron pair.
Since good leaving groups must readily accept electrons, weak bases are very good leaving groups.
The order of usefulness of halogens as leaving groups is: I > Br > Cl > F
1.67377x10-27 kilogram(kg) or 1.67377x 10-24 gram(g)
The number of energy levels to which an electron can jump depends on the amount of energy the electron possesses. Each energy level has a specific amount of energy an electron needs to have before it can be in there. So, if an electron doesn't have enough energy to be in that energy level then it won't jump to that higher level.